US-ian

Adjective

 * 1)  Of or pertaining to the United States of America.

Noun

 * 1)  An inhabitant or citizen of the United States of America.

Usage notes
A sporadic term. The hyphen tends to be used as an attributive, but as a substantive.

The similar-looking Usian, which differs in capitalization, is a separate word, one that never got beyond the proposal stage.